Tropic Thunder rumbles for Robert Downey Jr

Once he’s finally taken off the suit as Iron Man, Robert Downey Jr will be slapping on an army helmet – a fake one, at least – to play an egotistical actor in Ben Stiller’s latest directing job, Tropic Thunder.

The plot finds a big-budget war movie going completely off the rails as the actors end up becoming the soldiers they’re playing. Downey has signed on as the superbly named Kirk Lazarus, a four-time Oscar winner and anointed Greatest Actor Of His Generation. Shouldn’t be too much of a stretch, then…

Also agreeing to a tour of duty on the movie is Million Dollar Baby’s Jay Baruchel, soon to be seen in Judd Apatow’s Knocked Up sporting the strangest haircut of the year. In Tropic, Baruchel’s playing unknown young actor Kevin Sandusky.

With a script by Stiller, Justin Theroux and Etan Cohen, the movie kicks off shooting in July.